Equipment and Leasehold Improvements (Details) (USD $)
In Thousands, unless otherwise specified
9 Months Ended
Sep. 28, 2012
Dec. 30, 2011
Plant, equipment and leasehold improvements    
Equipment and leasehold improvements, Gross $ 22,500 $ 17,255
Less: accumulated depreciation and amortization (13,167) (11,876)
Equipment and leasehold improvements, net 9,333 5,379
Machinery and equipment [Member]
   
Plant, equipment and leasehold improvements    
Equipment and leasehold improvements, Gross 8,339 5,598
Machinery and equipment [Member] | Minimum [Member]
   
Plant, equipment and leasehold improvements    
Plant, equipment and leasehold improvements useful lives 5 years  
Machinery and equipment [Member] | Maximum [Member]
   
Plant, equipment and leasehold improvements    
Plant, equipment and leasehold improvements useful lives 10 years  
Computers, data processing and other equipment [Member]
   
Plant, equipment and leasehold improvements    
Equipment and leasehold improvements, Gross 4,970 3,941
Computers, data processing and other equipment [Member] | Minimum [Member]
   
Plant, equipment and leasehold improvements    
Plant, equipment and leasehold improvements useful lives 3 years  
Computers, data processing and other equipment [Member] | Maximum [Member]
   
Plant, equipment and leasehold improvements    
Plant, equipment and leasehold improvements useful lives 7 years  
Leasehold improvements [Member]
   
Plant, equipment and leasehold improvements    
Equipment and leasehold improvements, Gross 6,808 5,622
Leasehold improvements [Member] | Minimum [Member]
   
Plant, equipment and leasehold improvements    
Plant, equipment and leasehold improvements useful lives 7 years  
Leasehold improvements [Member] | Maximum [Member]
   
Plant, equipment and leasehold improvements    
Plant, equipment and leasehold improvements useful lives 15 years  
Furniture and fixtures [Member]
   
Plant, equipment and leasehold improvements    
Equipment and leasehold improvements, Gross 562 557
Plant, equipment and leasehold improvements useful lives 7 years  
Vehicles [Member]
   
Plant, equipment and leasehold improvements    
Equipment and leasehold improvements, Gross 501 496
Plant, equipment and leasehold improvements useful lives 5 years  
Other [Member]
   
Plant, equipment and leasehold improvements    
Equipment and leasehold improvements, Gross 85 85
Plant, equipment and leasehold improvements useful lives 7 years  
Construction-in-progress [Member]
   
Plant, equipment and leasehold improvements    
Equipment and leasehold improvements, Gross $ 1,235 $ 956